martin



(No Model.)

J. P.` MARTIN; GIONDUIT FOR ELECTRICAL WIRES. i No. 275,399. Y .Patented Apr. 10,1883.

N. Perma Phawmnummr un UNITED1 STATES PATENT .ONFICB..

JOHN 1?. 1\IART1N,` OF OHIOAeO,'1LLiNOis, Assie'NOa TO THE MARTIN ELEO- Taic WIRE OONDUOTINGr cOMPANY-,On SAME PLAGE.

-COND'uiT FOR ELECTRICAL WIRES.

SPECIFICATION forming part of Letters Patent No. 275,399, dated April 10, 1883 Application filed Junge, 1882. (No modem part of this specification.

l'Ihe object of my invention is to provide a non-combustible andv fire-proof conductor for electric-light and-other wires to be conveyed through buildings, that will prevent the deection of electricity and guard against danger of fire therefrom, as will' hereinafter be more fully describedin the 'specification and pointed out in the claims'.

In carrying out my invention I first prepare i a suitable insulating compound, preferably of marble-dust, plaster-of-paris, and glue-water, commonly called sizing,7 or the equivalent therefor, which I mold into tubes or plates of suitable length and of a size proportionate to the number of wires desired to be employed. After the compound is prepared I take shells or tubes made of paper or veneer, of the proper dimensions, and place them in rows perpendicular, using as cores brass rods placed in the center of the shells with their ends resting in bearings. Said rods should be well oiled to prevent the mixture adhering to them. The mix ture is then poured in at the upper ends of the shells, and while it is hardening the rods should be turned gently two or three times, so that they may be readily and easily withdrawn at the proper time, which is about twenty minutes after the mixture has been poured in. A short'sleeve may be slipped on one end of the'brass rods, which will, when the mixture is poured into the shell around the core, form a recess for the reception ofa glass or other tube. The other end of the tube or plate may be recessed after molding by using an ordinary countersink; or, instead of using the sleeve on the rod, both ends of the tube or plate may be recessed, as last described. The tubes -thus nels arranged parallel with each other may be molded in the same manner.

In lthe drawings, Figure l represents a View in cross-section, showing the conduit forming".V

a part ot' the linishing work of a building;

Fig. 2, a similar view, showing the conduit partially let into .the molding or other tinishing-piece of a building; Fig. 3, a similarvew,

showing the conduit concealed in the molding or other finishingpiece of a building; Fig. 4,

a similar view,showing a modified form of the conduit; Fig. 5, a longitudinal sectional view, showing the connecting-tubes; and Fig. 6, a view in cross-section, showing a modified form of conduit.

-A indicates the molding or other uishingpiece of a house or other building, and B the conduit designed to be let into or form a part of the same.

C is a tube or plate, made of an insulating compound, and provided with one or more passages, c,- for the reception ot1 the conducting-wires. A shell, D, made of paper, which may be ornamented, envelops said tube or plate, whereby additional strength is given tov the same, at the same time rendering them less liable to breakage, lnore convenient to handle, and enables them to be used in many cases without additional casings or moldings, especially when ornamented, as above stated. The ends of the tubes or plates are recessed, as shown at b, to receive a tube, E, of glass or other insulating material, thus making a continuous insulation through said tubes or plates.

My invention is especially designed for insulating electric light and other wires carried through buildings, where they may be concealed in the moldings, casings, or oth er parts of the structure, or they may be iucased, either wholly or in part, in ornamented strips or moldings especially constructed of any desired style, pattern, or finish for that purpose, and run or placed on or across the walls and ceilings, in which case, however, the moldings should have a space cut or stuck7 therein to fit and support the tubes.

When veneer shells are used as the envelope containing the insulating compound, they may be made of wood to match the Wood-work ofa building, and admit ofa high polish and finish. If it be desired, the paper shells may be made of any desired appearance and finish by coveringethem with an additional adheringshell made from wood veneer or appropriate paper or paper-Wood veneenand finishing them withv a hard polish. The tubes thus finished may be partly concealed in the molding and yet seem to be apart of it. In putting these insulating tubes in buildings, although they may be used Without moldings or other covering, I prefer to place them in some portion of structure or finishing work ot" the building, or in moldings especially prepared for them,or partly in both, as may be most convenient.

I have thus illustrated some ofthe ways in which the conduit maybe used in furtherance ofthe purposes for which it is adapted.

The conduit thus made and employed pos sesses many advantages, being both lire-proof and noncombustible, which are two essential features Where electric Wires are run through buildings. The compound herein described, used for making the insulating tubes or plates,

l purpose to have embodied in a Separate ap plication, and therefore lay noclnim to it in this application.

Having thus fully described my invention, \vhatIclaim,and desire to secure by Letters Patent, is-

l. The herein-described non-com bustible and lire-proof tube or plate, composed ofan insulating compound consisting ot' marble-dust, plaster-of-paris, and glue-water, and covered with a shell of paper or veneer, whereby additional strength is given to the saine,substantially as set forth.

2. An insulating non-combustible and tire proof conduit for electrical conductors, consisting of plates or tubes composed of an insulating compound consisting of niarbledust,plas

ter-of-paris, and glue-water, provided with pas sages, as described, to receive the conducting wires, said tubes or plates recessed at their made a part of the finishing work of a house 1 or other structure, substantially as set forth.

3. The insulating nonfcombustible and tirel kproof conduit, consisting of the tubes or plates' composed ofan insulating compound consisting of marble-dust, plaster-of-pars, and gluewater, provided with passages, as described, to receive the conducting-wires, said tubes or plates recessed at; their ends, the tubes of glass or equivalent non-conducting material, andthe shells of paper or veneer, the whole adopted to belet into or forni a part of the finishing work of a house or other building, for the purposes set forth.

4. The combination of the tubes or plates U, composed ofthe insulating compound consist ing of Imarble-dust, piaster-ot`paris, and gluewater, provided with passages, as described, to receive the conducting-wires, said tubes or plates recessed at their ends, the tubeA E, shell D, and finishing-piece A, substantially as and for the purpose set forth.

5. As an article of manufacture, an electrical conduit composed of an insulating compound `comsisting of marble-dust, plaster-of-` paris, and glue-water, molded into tubesor plates provided with passages, said tubes or plates being incased within an ornamented paper or veneer shell, the Whole constructed.

as described, whereby it may be let into or form a part of the finishing work of a house or other structure,as and for the purposes set forth.

In testimony that l claim the foregoing l have hereunto set my hand and seal this 26th day of May, A. D. 1882.

JOHN F. MARTIN. [L. 5.]

Witnesses:

N. I. FITCH,- J. B. WHITE. 

